A deal is a deal, right? Well, Level 3 Communications' (Nasdaq: LVLT) proposed acquisition of Global Crossing (Nasdaq: GLBC) is far from done as the Justice Department is now expanding its investigation of the deal.

Each of the service providers received a request for information concerning the takeover under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 on Tuesday.

Both Level 3 and Global Crossing said in separately issued statements that they will respond to the investigation but still expect the $3 billion deal to close by the end of the year.

In June, Level 3 petitioned to the FCC that the acquisition of Global Crossing won't cause any other carriers to raise competition or public interest issues.

However, other competitors like XO Communications (OTC BB: XOHO) aren't so sure.

XO, a major business services competitor to both Level 3 and Global Crossing, has also filed comments with the FCC that argue the combined company will monopolize the tier one Internet backbone market.

"By bringing together the two leading Internet backbone providers ("IBPs"), the transaction will create a "global colossus" that will dominate the market, leading to significantly higher prices and decreased service quality and innovation for all other IBPs and their customers," said XO in an FCC filing.

In addition to XO and the DOJ, the FBI and the Department of Homeland Security have also asked the FCC to delay making a final decision on the deal.

"DOJ, DHS, and FBI ... are currently reviewing this matter for any national security, law enforcement, and public safety issues but have not yet completed that effort," the Justice Department said in a filing on Monday. "We therefore request that the Commission defer action until such time as the Agencies notify the Commission of the completion of their review and, based on the results of such review, request appropriate action by the Commission."

For more:- see the Level 3 release- see the Global Crossing release- Rochester Business Journal has this article- here's XO's FCC filing (pdf)